<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <style>
        .my-table, th, td{
            border: 1px solid gray;
            border-collapse: collapse;
        }

        .my-table{
            width: 75%;
        }

        .my-table th,td{
            width: 300px;
            height: 50px;
            text-align: center;
            vertical-align: middle;
        }

        .my-table th{
            color: #ffffff;
            background-color: #343434;
            position: relative;
        }

        .my-table .arrows{
            position: absolute;
            right: 40px;
            top: 15px;
        }
        .arrows div.up, div.down {
            width: 0;
            height: 0;
            border-left: 7px solid transparent;
            border-right: 7px solid transparent;

            position: relative;
            cursor: pointer;
        }

        .arrows div.up{
            border-bottom: 10px solid #ffffff;
        }
        .arrows div.down{
            border-top: 10px solid #ffffff;
            margin-top: 5px;
        }

        div.up:hover{
            border-bottom: 10px solid orange;
        }

        div.down:hover{
            border-top: 10px solid orange;
        }

    </style>
</head>
<body id="container">

<script src="task.js"></script>
</body>
</html>